Implement JSON modules (#1711)

Jint.Tests.Test262/Test262Harness.settings.json

@@ -11,7 +11,6 @@
     "generators",
     "import-assertions",
     "iterator-helpers",
-    "json-modules",
     "regexp-duplicate-named-groups",
     "regexp-lookbehind",
     "regexp-unicode-property-escapes",

Jint.Tests.Test262/Test262ModuleLoader.cs

@@ -1,14 +1,12 @@
 #nullable enable
 
-using Esprima;
-using Esprima.Ast;
 using Jint.Runtime;
 using Jint.Runtime.Modules;
 using Zio;
 
 namespace Jint.Tests.Test262;
 
-internal sealed class Test262ModuleLoader : IModuleLoader
+internal sealed class Test262ModuleLoader : ModuleLoader
 {
     private readonly IFileSystem _fileSystem;
     private readonly string _basePath;
@@ -19,44 +17,22 @@ public Test262ModuleLoader(IFileSystem fileSystem, string basePath)
         _basePath = "/test/" + basePath.TrimStart('\\').TrimStart('/');
     }
 
-    public ResolvedSpecifier Resolve(string? referencingModuleLocation, string specifier)
+    public override ResolvedSpecifier Resolve(string? referencingModuleLocation, ModuleRequest moduleRequest)
     {
-        return new ResolvedSpecifier(referencingModuleLocation ?? "", specifier ?? "", null, SpecifierType.Bare);
+        return new ResolvedSpecifier(moduleRequest, moduleRequest.Specifier, null, SpecifierType.Bare);
     }
 
-    public Module LoadModule(Engine engine, ResolvedSpecifier resolved)
+    protected override string LoadModuleContents(Engine engine, ResolvedSpecifier resolved)
     {
-        Module module;
-        try
+        lock (_fileSystem)
         {
-            string code;
-            lock (_fileSystem)
+            var fileName = Path.Combine(_basePath, resolved.Key).Replace('\\', '/');
+            if (!_fileSystem.FileExists(fileName))
             {
-                var fileName = Path.Combine(_basePath, resolved.Key).Replace('\\', '/');
-                using var stream = new StreamReader(_fileSystem.OpenFile(fileName, FileMode.Open, FileAccess.Read));
-                code = stream.ReadToEnd();
+                ExceptionHelper.ThrowModuleResolutionException("Module Not Found", resolved.ModuleRequest.Specifier, parent: null, fileName);
             }
-
-            var parserOptions = new ParserOptions
-            {
-                RegExpParseMode = RegExpParseMode.AdaptToInterpreted,
-                Tolerant = true
-            };
-
-            module = new JavaScriptParser(parserOptions).ParseModule(code, source: resolved.Uri?.LocalPath!);
-        }
-        catch (ParserException ex)
-        {
-            ExceptionHelper.ThrowSyntaxError(engine.Realm, $"Error while loading module: error in module '{resolved.Uri?.LocalPath}': {ex.Error}");
-            module = null;
-        }
-        catch (Exception ex)
-        {
-            var message = $"Could not load module {resolved.Uri?.LocalPath}: {ex.Message}";
-            ExceptionHelper.ThrowJavaScriptException(engine, message, (Location) default);
-            module = null;
+            using var stream = new StreamReader(_fileSystem.OpenFile(fileName, FileMode.Open, FileAccess.Read));
+            return stream.ReadToEnd();
         }
-
-        return module;
     }
 }

Jint.Tests/Runtime/Modules/DefaultModuleLoaderTests.cs

@@ -5,17 +5,17 @@ namespace Jint.Tests.Runtime.Modules;
 public class DefaultModuleLoaderTests
 {
     [Theory]
-    [InlineData("./other.js", @"file:///project/folder/other.js")]
-    [InlineData("../model/other.js", @"file:///project/model/other.js")]
-    [InlineData("/project/model/other.js", @"file:///project/model/other.js")]
-    [InlineData("file:///project/model/other.js", @"file:///project/model/other.js")]
+    [InlineData("./other.js", "file:///project/folder/other.js")]
+    [InlineData("../model/other.js", "file:///project/model/other.js")]
+    [InlineData("/project/model/other.js", "file:///project/model/other.js")]
+    [InlineData("file:///project/model/other.js", "file:///project/model/other.js")]
     public void ShouldResolveRelativePaths(string specifier, string expectedUri)
     {
         var resolver = new DefaultModuleLoader("file:///project");
 
-        var resolved = resolver.Resolve("file:///project/folder/script.js", specifier);
+        var resolved = resolver.Resolve("file:///project/folder/script.js", new ModuleRequest(specifier, []));
 
-        Assert.Equal(specifier, resolved.Specifier);
+        Assert.Equal(specifier, resolved.ModuleRequest.Specifier);
         Assert.Equal(expectedUri, resolved.Key);
         Assert.Equal(expectedUri, resolved.Uri?.AbsoluteUri);
         Assert.Equal(SpecifierType.RelativeOrAbsolute, resolved.Type);
@@ -30,7 +30,7 @@ public void ShouldRejectPathsOutsideOfBasePath(string specifier)
     {
         var resolver = new DefaultModuleLoader("file:///project");
 
-        var exc = Assert.Throws<ModuleResolutionException>(() => resolver.Resolve("file:///project/folder/script.js", specifier));
+        var exc = Assert.Throws<ModuleResolutionException>(() => resolver.Resolve("file:///project/folder/script.js", new ModuleRequest(specifier, [])));
         Assert.StartsWith(exc.ResolverAlgorithmError, "Unauthorized Module Path");
         Assert.StartsWith(exc.Specifier, specifier);
     }
@@ -40,9 +40,9 @@ public void ShouldResolveBareSpecifiers()
     {
         var resolver = new DefaultModuleLoader("/");
 
-        var resolved = resolver.Resolve(null, "my-module");
+        var resolved = resolver.Resolve(null, new ModuleRequest("my-module", []));
 
-        Assert.Equal("my-module", resolved.Specifier);
+        Assert.Equal("my-module", resolved.ModuleRequest.Specifier);
         Assert.Equal("my-module", resolved.Key);
         Assert.Equal(null, resolved.Uri?.AbsoluteUri);
         Assert.Equal(SpecifierType.Bare, resolved.Type);

Jint/Engine.Modules.cs

@@ -23,9 +23,10 @@ public partial class Engine
             return _executionContexts?.GetActiveScriptOrModule();
         }
 
-        internal ModuleRecord LoadModule(string? referencingModuleLocation, string specifier)
+        internal ModuleRecord LoadModule(string? referencingModuleLocation, ModuleRequest request)
         {
-            var moduleResolution = ModuleLoader.Resolve(referencingModuleLocation, specifier);
+            var specifier = request.Specifier;
+            var moduleResolution = ModuleLoader.Resolve(referencingModuleLocation, request);
 
             if (_modules.TryGetValue(moduleResolution.Key, out var module))
             {
@@ -59,10 +60,9 @@ private BuilderModuleRecord LoadFromBuilder(string specifier, ModuleBuilder modu
             return module;
         }
 
-        private SourceTextModuleRecord LoadFromModuleLoader(ResolvedSpecifier moduleResolution)
+        private ModuleRecord LoadFromModuleLoader(ResolvedSpecifier moduleResolution)
         {
-            var parsedModule = ModuleLoader.LoadModule(this, moduleResolution);
-            var module = new SourceTextModuleRecord(this, Realm, parsedModule, moduleResolution.Uri?.LocalPath, false);
+            var module = ModuleLoader.LoadModule(this, moduleResolution);
             _modules[moduleResolution.Key] = module;
             return module;
         }
@@ -88,30 +88,35 @@ public void AddModule(string specifier, ModuleBuilder moduleBuilder)
 
         public ObjectInstance ImportModule(string specifier)
         {
-            return ImportModule(specifier, null);
+            return ImportModule(specifier, referencingModuleLocation: null);
         }
 
         internal ObjectInstance ImportModule(string specifier, string? referencingModuleLocation)
         {
-            var moduleResolution = ModuleLoader.Resolve(referencingModuleLocation, specifier);
+            return ImportModule(new ModuleRequest(specifier, []), referencingModuleLocation);
+        }
+
+        internal ObjectInstance ImportModule(ModuleRequest request, string? referencingModuleLocation)
+        {
+            var moduleResolution = ModuleLoader.Resolve(referencingModuleLocation, request);
 
             if (!_modules.TryGetValue(moduleResolution.Key, out var module))
             {
-                module = LoadModule(null, specifier);
+                module = LoadModule(referencingModuleLocation: null, request);
             }
 
             if (module is not CyclicModuleRecord cyclicModule)
             {
-                LinkModule(specifier, module);
-                EvaluateModule(specifier, module);
+                LinkModule(request.Specifier, module);
+                EvaluateModule(request.Specifier, module);
             }
             else if (cyclicModule.Status == ModuleStatus.Unlinked)
             {
-                LinkModule(specifier, cyclicModule);
+                LinkModule(request.Specifier, cyclicModule);
 
                 if (cyclicModule.Status == ModuleStatus.Linked)
                 {
-                    ExecuteWithConstraints(true, () => EvaluateModule(specifier, cyclicModule));
+                    ExecuteWithConstraints(true, () => EvaluateModule(request.Specifier, cyclicModule));
                 }
 
                 if (cyclicModule.Status != ModuleStatus.Evaluated)

Jint/EsprimaExtensions.cs

@@ -330,25 +330,42 @@ internal static void GetImportEntries(this ImportDeclaration import, List<Import
         {
             var source = import.Source.StringValue!;
             var specifiers = import.Specifiers;
-            requestedModules.Add(new ModuleRequest(source, []));
+            var attributes = GetAttributes(import.Attributes);
+            requestedModules.Add(new ModuleRequest(source, attributes));
 
             foreach (var specifier in specifiers)
             {
                 switch (specifier)
                 {
                     case ImportNamespaceSpecifier namespaceSpecifier:
-                        importEntries.Add(new ImportEntry(source, "*", namespaceSpecifier.Local.GetModuleKey()));
+                        importEntries.Add(new ImportEntry(new ModuleRequest(source, attributes), "*", namespaceSpecifier.Local.GetModuleKey()));
                         break;
                     case ImportSpecifier importSpecifier:
-                        importEntries.Add(new ImportEntry(source, importSpecifier.Imported.GetModuleKey(), importSpecifier.Local.GetModuleKey()));
+                        importEntries.Add(new ImportEntry(new ModuleRequest(source, attributes), importSpecifier.Imported.GetModuleKey(), importSpecifier.Local.GetModuleKey()!));
                         break;
                     case ImportDefaultSpecifier defaultSpecifier:
-                        importEntries.Add(new ImportEntry(source, "default", defaultSpecifier.Local.GetModuleKey()));
+                        importEntries.Add(new ImportEntry(new ModuleRequest(source, attributes), "default", defaultSpecifier.Local.GetModuleKey()));
                         break;
                 }
             }
         }
 
+        private static ModuleImportAttribute[] GetAttributes(in NodeList<ImportAttribute> importAttributes)
+        {
+            if (importAttributes.Count == 0)
+            {
+                return Array.Empty<ModuleImportAttribute>();
+            }
+
+            var attributes = new ModuleImportAttribute[importAttributes.Count];
+            for (var i = 0; i < importAttributes.Count; i++)
+            {
+                var attribute = importAttributes[i];
+                attributes[i] = new ModuleImportAttribute(attribute.Key.ToString(), attribute.Value.StringValue!);
+            }
+            return attributes;
+        }
+
         internal static void GetExportEntries(this ExportDeclaration export, List<ExportEntry> exportEntries, HashSet<ModuleRequest> requestedModules)
         {
             switch (export)
@@ -359,13 +376,17 @@ internal static void GetExportEntries(this ExportDeclaration export, List<Export
                 case ExportAllDeclaration allDeclaration:
                     //Note: there is a pending PR for Esprima to support exporting an imported modules content as a namespace i.e. 'export * as ns from "mod"'
                     requestedModules.Add(new ModuleRequest(allDeclaration.Source.StringValue!, []));
-                    exportEntries.Add(new(allDeclaration.Exported?.GetModuleKey(), allDeclaration.Source.StringValue, "*", null));
+                    exportEntries.Add(new(allDeclaration.Exported?.GetModuleKey(), new ModuleRequest(allDeclaration.Source.StringValue!, []), "*", null));
                     break;
                 case ExportNamedDeclaration namedDeclaration:
                     ref readonly var specifiers = ref namedDeclaration.Specifiers;
                     if (specifiers.Count == 0)
                     {
-                        GetExportEntries(false, namedDeclaration.Declaration!, exportEntries, namedDeclaration.Source?.StringValue);
+                        ModuleRequest? moduleRequest = namedDeclaration.Source != null
+                            ? new ModuleRequest(namedDeclaration.Source?.StringValue!, [])
+                            : null;
+
+                        GetExportEntries(false, namedDeclaration.Declaration!, exportEntries, moduleRequest);
                     }
                     else
                     {
@@ -374,7 +395,7 @@ internal static void GetExportEntries(this ExportDeclaration export, List<Export
                             var specifier = specifiers[i];
                             if (namedDeclaration.Source != null)
                             {
-                                exportEntries.Add(new(specifier.Exported.GetModuleKey(), namedDeclaration.Source.StringValue, specifier.Local.GetModuleKey(), null));
+                                exportEntries.Add(new(specifier.Exported.GetModuleKey(), new ModuleRequest(namedDeclaration.Source.StringValue!, []), specifier.Local.GetModuleKey(), null));
                             }
                             else
                             {
@@ -392,7 +413,7 @@ internal static void GetExportEntries(this ExportDeclaration export, List<Export
             }
         }
 
-        private static void GetExportEntries(bool defaultExport, StatementListItem declaration, List<ExportEntry> exportEntries, string? moduleRequest = null)
+        private static void GetExportEntries(bool defaultExport, StatementListItem declaration, List<ExportEntry> exportEntries, ModuleRequest? moduleRequest = null)
         {
             var names = GetExportNames(declaration);
 
@@ -444,9 +465,9 @@ private static List<string> GetExportNames(StatementListItem declaration)
             return result;
         }
 
-        private static string? GetModuleKey(this Expression expression)
+        private static string GetModuleKey(this Expression expression)
         {
-            return (expression as Identifier)?.Name ?? (expression as Literal)?.StringValue;
+            return (expression as Identifier)?.Name ?? (expression as Literal)!.StringValue!;
         }
 
         internal readonly record struct Record(JsValue Key, ScriptFunctionInstance Closure);

Jint/HoistingScope.cs

@@ -134,7 +134,7 @@ public static void GetImportsAndExports(
 
             importEntries = treeWalker._importEntries;
             requestedModules = treeWalker._requestedModules ?? [];
-            var importedBoundNames = new HashSet<string>(StringComparer.Ordinal);
+            var importedBoundNames = new HashSet<string?>(StringComparer.Ordinal);
 
             if (importEntries != null)
             {

Jint/Native/ShadowRealm/ShadowRealm.cs

@@ -277,7 +277,7 @@ internal JsValue ShadowRealmImportValue(
         // 4. If runningContext is not already suspended, suspend runningContext.
 
         _engine.EnterExecutionContext(_executionContext);
-        _engine._host.LoadImportedModule(null, new ModuleRequest(specifierString, new List<KeyValuePair<string, JsValue>>()), innerCapability);
+        _engine._host.LoadImportedModule(null, new ModuleRequest(specifierString, []), innerCapability);
         _engine.LeaveExecutionContext();
 
         var onFulfilled = new StepsFunction(_engine, callerRealm, exportNameString);

Jint/Runtime/Environments/ModuleEnvironmentRecord.cs

@@ -51,7 +51,7 @@ internal override bool TryGetBinding(BindingName name, bool strict, out Binding
     {
         if (_importBindings.TryGetValue(name.Key, out var indirectBinding))
         {
-            value = indirectBinding.Module._environment.GetBindingValue(indirectBinding.BindingName, true);
+            value = indirectBinding.Module._environment.GetBindingValue(indirectBinding.BindingName, strict: true);
             binding = new(value, canBeDeleted: false, mutable: false, strict: true);
             return true;
         }

Jint/Runtime/Host.cs

@@ -118,9 +118,9 @@ public virtual void EnsureCanCompileStrings(Realm callerRealm, Realm evalRealm)
         /// <summary>
         /// https://tc39.es/ecma262/#sec-GetImportedModule
         /// </summary>
-        internal virtual ModuleRecord GetImportedModule(IScriptOrModule? referrer, string specifier)
+        internal virtual ModuleRecord GetImportedModule(IScriptOrModule? referrer, ModuleRequest request)
         {
-            return Engine.LoadModule(referrer?.Location, specifier);
+            return Engine.LoadModule(referrer?.Location, request);
         }
 
         /// <summary>
@@ -151,7 +151,7 @@ internal virtual void FinishLoadingImportedModule(IScriptOrModule? referrer, Mod
         {
             var onFulfilled = new ClrFunctionInstance(Engine, "", (thisObj, args) =>
             {
-                var moduleRecord = GetImportedModule(referrer, moduleRequest.Specifier);
+                var moduleRecord = GetImportedModule(referrer, moduleRequest);
                 try
                 {
                     var ns = ModuleRecord.GetModuleNamespace(moduleRecord);